package net.xdclass.util;

import com.google.common.hash.Hashing;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.MessageDigest;
import java.util.*;

/**
 * 小滴课堂,愿景：让技术不再难学
 *
 * @Description
 * @Author 二当家小D
 * @Remark 有问题直接联系我，源码-笔记-技术交流群
 * @Version 1.0
 **/


@Slf4j
public class CommonUtil {
	/**
	 * 获取ip
	 *
	 * @param request
	 * @return
	 */
	public static String getIpAddr(HttpServletRequest request) {
		String ipAddress = null;
		try {
			ipAddress = request.getHeader("x-forwarded-for");
			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getHeader("Proxy-Client-IP");
			}
			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getHeader("WL-Proxy-Client-IP");
			}
			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getRemoteAddr();
				if (ipAddress.equals("127.0.0.1")) {
					// 根据网卡取本机配置的IP
					InetAddress inet = null;
					try {
						inet = InetAddress.getLocalHost();
					} catch (UnknownHostException e) {
						e.printStackTrace();
					}
					ipAddress = inet.getHostAddress();
				}
			}
			// 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
			if (ipAddress != null && ipAddress.length() > 15) {
				// "***.***.***.***".length()
				// = 15
				if (ipAddress.indexOf(",") > 0) {
					ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
				}
			}
		} catch (Exception e) {
			ipAddress = "";
		}
		return ipAddress;
	}


	/**
	 * 获取全部请求头
	 *
	 * @param request
	 * @return
	 */
	public static Map<String, String> getAllRequestHeader(HttpServletRequest request) {
		Enumeration<String> headerNames = request.getHeaderNames();
		Map<String, String> map = new HashMap<>();
		while (headerNames.hasMoreElements()) {
			String key = (String) headerNames.nextElement();
			//根据名称获取请求头的值
			String value = request.getHeader(key);
			map.put(key, value);
		}

		return map;
	}


	/**
	 * MD5加密
	 *
	 * @param data
	 * @return
	 */
	public static String MD5(String data) {
		try {
			MessageDigest md = MessageDigest.getInstance("MD5");
			byte[] array = md.digest(data.getBytes("UTF-8"));
			StringBuilder sb = new StringBuilder();
			for (byte item : array) {
				sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
			}

			return sb.toString().toUpperCase();
		} catch (Exception exception) {
		}
		return null;

	}


	/**
	 * 获取验证码随机数
	 *
	 * @param length
	 * @return
	 */
	public static String getRandomCode(int length) {

		String sources = "0123456789";
		Random random = new Random();
		StringBuilder sb = new StringBuilder();
		for (int j = 0; j < length; j++) {
			sb.append(sources.charAt(random.nextInt(9)));
		}
		return sb.toString();
	}


	/**
	 * 获取当前时间戳
	 *
	 * @return
	 */
	public static long getCurrentTimestamp() {
		return System.currentTimeMillis();
	}


	/**
	 * 生成uuid
	 *
	 * @return
	 */
	public static String generateUUID() {
		return UUID.randomUUID().toString().replaceAll("-", "").substring(0, 32);
	}

	/**
	 * 获取随机长度的串
	 *
	 * @param length
	 * @return
	 */
	private static final String ALL_CHAR_NUM = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

	public static String getStringNumRandom(int length) {
		//生成随机数字和字母,
		Random random = new Random();
		StringBuilder saltString = new StringBuilder(length);
		for (int i = 1; i <= length; ++i) {
			saltString.append(ALL_CHAR_NUM.charAt(random.nextInt(ALL_CHAR_NUM.length())));
		}
		return saltString.toString();
	}


	/**
	 * 响应json数据给前端
	 *
	 * @param response
	 * @param obj
	 */
	public static void sendJsonMessage(HttpServletResponse response, Object obj) {

		response.setContentType("application/json; charset=utf-8");

		try (PrintWriter writer = response.getWriter()) {
			writer.print(JsonUtil.obj2Json(obj));
			response.flushBuffer();

		} catch (IOException e) {
			log.warn("响应json数据给前端异常:{}", e);
		}
	}
	 public static long getMurmur(String url){
		long murmur = Hashing.murmur3_32().hashUnencodedChars(url).padToLong();
		return murmur;
	}


	public static String addUrlPrefix(String url){
		return  IdUtil.generateId()+"||"+url;
	}

	public static String removePrefix(String url){
		int index = url.indexOf("||");
		String originalUrl = url.substring(index+2);
		return originalUrl;
	}

	public static String addUrlPrefixVersion(String url){
		int index = url.indexOf("||");
		String originalUrl = url.substring(index+2);
		String version = url.substring(0,index+1);
		Long newVersion = Long.parseLong(version)+1;
		String newUrl = newVersion+"||"+originalUrl;
		return newUrl;
	}

	/**
	 * 10进制转62进制
	 * @param num
	 * @return
	 */
	 public static String  encodeTobase62(long num){
       String chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
       StringBuffer sb = new StringBuffer();
       do{ int i= Math.abs((int) num%62);
          sb.append(chars.charAt(i));
          num = num/62;
       }
       while(num >0);
       return sb.reverse().toString();
	 }

}